"Incredible night with friends and family!" she Tweeted, along with a selfie of the happy couple.

In an interview on KiroRadio with The Bachelor's Jason and Molly Mesnick on Friday, Hartsock, 27, said she was looking forward to partying at the DeLille Cellars winery in Woodinville, Wash.

"My parents are flying in from Ohio," she said. "There's about 40 people coming. I'm so excited."

The Mesnicks, who met on season 13 of The Bachelor, attended Saturday's event. "Celebrating the love of @DesHartsock & @ChrisRSiegfried this evening," Molly Tweeted. "BEAUTIFUL party...love these guys!"

Hartsock and Siegfried, who will wed later this year, are enjoying wedding-planning mode. "We have little things planned," she said in the radio interview. "Now it's working on the bigger things!" Added Siegfried: "I'm somewhere in between hands off and highly involved. I'll offer my two cents. I just want it to be an awesome dance party."